A journey down the rabbit hole of Rubik's-style puzzles

The Mouse OLLs (##3, 4) are hard. Not so much their execution (certainly the Sexy Move variants aren’t all that bad), but orientation. Where does that corner go? Top-right? Bottom left? And what about that side with just the un-oriented edge? Which is Mouse and which is Anti-?

Having concentrated on these OLLs quite a bit, I now no longer mind them. Here’s a simple table and video tutorial — its soundtrack a tribute to Lou Reed, RIP — followed after the jump by further explanation.

There are two basic approaches to these OLLs. The Sexy Move-based algorithms are easy to remember (with only one move different between the mirrors), but clunkier to execute. The Sune-based algorithms are harder to remember but faster and smoother to execute. The key to these OLLs is knowing how to orient the U face before execution and then which of the mirrors to apply.

Sexy Move Variants

Both mirrors are relatively simple — with two Sexy Moves, each bookended with F(‘) moves and joined by an orienting middle move. The only challenges are how to orient the cube and determining which orienting move — U or U’ — to use.

For the Sexy Move variations, the correctly-oriented (up-facing) corner should be placed in the right layer. Whether that goes in U/R/B or U/R/F depends on the face with only an un-oriented edge (the other three each have both an un-oriented edge and an un-oriented corner). As demonstrated in the figure to the right, that un-oriented edge should face front or back, not left or right.

From there, it’s easy to determine whether to use a U or U’. If it takes a U to move that un-oriented edge into the right layer, then use a U in the middle of the algorithm; if it would take a U’ to move it into the right layer, use a U’. Simple, right?

Sune Variants

Although these took longer to learn, they flow more easily and execute more quickly for me. In contrast to the nearly identical Sexy Move mirrors, the mirrors here are relatively distinct — with only the M starts, M’ finishes, and Rw(‘)s in common.

Orienting the cube for the Sune variants is not dissimilar to setting up for the Sexy Move ones, only the oriented corner goes in the F face. Whether it goes in U/R/F or U/L/F depends, again, on the face with only the un-oriented edge. That edge should face left or right, not front or back — as in the diagram to the right.

From there, I have no clever mnemonic. If the un-oriented edge faces left, it’s Sune-based (R U R’ U); if it faces right, it’s anti-Sune-based (U’ R U’ R’). As I said, these are the harder variants….